Concrete pavement grooving process and apparatus



June 23, 1970 G. E. PERKINS CONCRETE PAVEMENT GROOVING PROCESS AND APPARATUS Filed June 17, 1968 z/en fax:

United States Patent O 3,516,340 CONCRETE PAVEMENT GROOVIN G PROCESS AND APPARATUS Glen E. Perkins, 1428 40th Ave., Rock Island, Ill. 61201 Filed June 17, 1968, Ser. No. 737,430 Int. Cl. E01c 19/22 US. Cl. 94-45 3 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for forming transversely extending grooves in concrete pavement, such as an airport runway, by drawing transversely over and pressing onto newly laid concrete a molding bar carrying a plurality of spaced downwardly projecting ribs disposed transversely of the pavement.

Recently there have been skidding accidents of planes landng in rain storms. These are caused because of the low skid-resistance of pavement when wet and hydroplaning when water builds up on pavement.

The Federal Aviation Anthority (FAA) has found by sawing transverse grooves in a runway with a concrete saw, that this allows the water to get off of the top or surface of the runway, rather than having to drain all the way to the edge of the runway, so the skid resistance will remain and hydroplaning will be mitigated.

It is the object of the present invention to provide a novel method and means for the formation of such transverse grooves in concrete pavement by molding said grooves thereinto while the concrete is still in a plastic condition.

In accordance with the present invention, I provide a molding plate adapted to be reciprocated transversely of the pavement and provided on its underface with a plurality of spaced downwardly projecting ribs disposed transversely of the pavement, and means for pressing the plate onto the pavement surface so there is a simultaneous formation of the grooves and smoothing of the intervening surfaces therebetween so as to Conveniently, economically and quickly form a grooved but smooth pavement surface.

To mold grooves transversely in pavement, the individual grooving ribs are pointed on either end, attached to a rigid plate, such as a channel, of sufficient length so the assembly will serve as a straight edge or extrusion meter when in contact with the concrete surface. This molding device is mounted under a carriage of a selfpropelled machine, ridng either on forms in form paving, or on grade in case of slip-form paving. The molding device is Suspended from the frame of the machine, lowered into contact with the surface of the concrete slab, and moved from one edge to the opposite edge. The device is then picked up and held `while the machine moves forward the length of the molding device. The machine then stops, the molding device is lowered to make contact with the slab, and the device is then moved from said opposite edge to said one edge of the runway pavement. The device may thus be operated upon all or selected portions of the runway, as desired, to mold grooves transversely into the pavement.

Other objects and advantages of the present invention, its details of Construction, arrangement of parts and method thereof will be apparent from the following specification and accompanying drawings wherein:

FIG. 1 is a diagrammatic side elevational View of a paving machine embodying the invention;

FIG. 2 is a transverse section on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary bottom view of the groove molding bar or plate;

FIG. 4 is a section on the line 4-4 of FIG. 3;

FIG. 5 is a fragmentary perspective top elevational View of the groove molding plate; and

FIG. 6 is a fragmentary perspective view of a grooved pavement surface made in accordance with the present invention.

Referring to the drawings, the reference numeral 10 generally designates a paving machine adapted to be used in conjunction with a slip-form paver such as that shown in Pat. No. 2,976,783; the illustrated machine ridng on the grade behind the paver and providing a groove molding bar 11 as essentially the final concrete molding element of the assembly. Alternatively, the machine could be one devised to ride on side forms in trailng relation to a form type paver.

The illustrated machine 10 of FIG. l comprises a frame portion 12 supporting a prime mover 13 for variable speed drive of the machine as a whole and the molding bar or plate 11.

The frame portion 12 comprises spaced transverse and longitudinal beams joined to opposite slip forms 7 about which are disposed articulated tracks 8 engaged at their opposed ends about sprocket wheels 9 driven through prime mover 13, and which may be driven jontly or separately as is well known.

Adjacent the front and rear thereof, the frame 12 includes parallel transverse beams 14, such as Channels or the like, which serve as rails for the opposite ends of a longitudinally extending, transversely reciprocable carriage 15, which may also be in the form of a channel. Mounted adjacent the ends of each beam 14 are a pair of sprockets 16 over which a chain 17 is trained, the chain being connected at its opposite ends to the carriage 15. One sprocket of each pair is coupled to the prime mover, by a reversible rnechancal clutch (not shown) in the case of a mechanical drive, or is provided with a reversible electrical motor (not shown) in the case of an electrical drive, which is under the control of the machine operator whereby the chain may be reversely driven to reciprocate the carriage 15 transversely of the machine frame, and thus transversely of the pavement laid by the immediately preceding paver.

Mounted on and depending from the carriage 15 are a plurality of hydraulic or pnuematic cylinders 20 which are connected to the molding bar or plate 11 and adapted to raise and lower the same into and out of contact with the still plastic or molda-ble concrete.

The molding bar or plate 11 is a rigid structural mernber, such as a channel, of a width sufficient to provide an ironing or extruding influence on the plastic concrete and of a length to provide a straight edge eifect and a suiciently high groove production rate that the machine 10 can keep pace with the movement of the cooperating paver. The plate width may for example vary from 8 to 16 inches and its length from 8 to 16 feet.

The plate or bar 11 carries on its underface a plurality of parallel ribs 28 and the intervening surfaces of the bar between the ribs 28 is imperforate and smooth. The ribs extend from side to side of the plate 11, are tapered or pointed at both ends to facilitate reciprocatory movement, and are downwardly tapered to facilitate their entry into and removal from the plastic concrete. The ribs may be V-shaped, U-shaped, half-round (as shown heren) or practcally any other cross-sectional shape desired. The depth and spacing of the ribs should be correlated to avoid weakening of the upper surface portion of the finished pavement, but otherwise may be of substantially any depth and spacing desired; provided however that the spacing should preferably be equal to or greater than the largest of the coarse aggregate in the concrete so that the aggregate can be wedged into the spaces and pass between the ribs without being torn out of the concrete mass. Onehalf inch half-round ribs on one and one-half inch and one and three-quarter inch centers have worked well, as have comparable V-shaped ribs.

In use, the machine trails immediately behind the paver so as to work on the concrete while it is still plastic. Assuming the carriage to be located adjacent one end of the tracks 14 and the molding plate or meter 11 to be raised, the machine 10 is moved to a preselected location along the pavement and is stopped. The operator then actuates the cylinders to drive the plate 11 downwardly to force the ribs 28 to their full depth into the concrete adjacent one edge of the pavement, and to bring the lower face of the plate into firm pressing engagement with the surface of the pavement. The drive sprockets 16 are then coupled to the drive means therefor to cause the chain 17 to pull the carriage 15, cylinders 20 and plate 11 transversely across the pavement to adjacent the opposite edge thereof, whereby grooves 30 are molded into the pavement and the surface of the pavement between the grooves is compressvely smoothed to leave a smooth but grooved pavement surface as shown in FIG. 6.

When the carriage 15 reaches the end of the tracks 14 opposite the starting position, the operator stops the chain drive 16-17, operates the cylinders 20 to raise the plate 11 clear of the pavement, advances the machine the length of the plate 11 and then repeats the above de-' scribed operation, except moving the plate in the opposite direction, thereby to groove the next succeeding longitudinal segment of the pavement.

The grooves may extend over the full width of the pavement as above described, or may, by appropriate operation of the chain drive 16-17 and/ or the cylinders 20, extend over only a selected portion or one or more selected transverse areas of the pavement surface. Similarly, by controlling the sequential advancing movements of the machine 10, the entirety or only selected longitudinal areas of the pavement may be grooved. Thus, potentially dangerous areas such as landing areas, turns, curves, intersections, interchanges, etc. can be protectively grooved while leaving the rest of the pavement ungrooved. Specifically, the bar 11 could normally be elevated above the concrete surface and be pressed downwardly by said cylinders or jacks 20 into molding contact with said surface only in those areas where groovng was specified.

It is preferable that the groovng ribs be mounted on or comprise the final concrete molding element of the paving apparatus. However, this does not eliminate or render ineffectual conventional texturing or other final surface treatment of the concrete, such as a burlap or light broom drag. It is specifically contemplated that the groovng means would normally be followed by a burlap drag, which would texture the concrete surface between the grooves but not cause the plastic concrete to be displaced into the grooves.

Thus, while I have shown and described the preferred embodiment of my invention, it will be understood by those skilled in the art that changes may be made in the details thereof without departing from its scope as comprehended by the following claims.

I claim:

1. The method of forming a series of spaced parallel grooves in the surface of newly laid concrete pavement which comprises progressively moving over the pavement a molding plate having an appreciable dimension in the direction of movement and having a plurality of spaced downwardly propecting ribs of shallow depth on the lower surface thereof, and simultaneously pressing said plate against the upper surface of the pavement to imbed said ribs to their full depth in the pavement and to press the intervening areas of said plate against the surface of the pavement with substantial pressure, the plate extending longitudinally of the pavement and the ribs transversely thereof, and characterized by the steps of pressing the plate onto the surface, moving the plate transversely across the pavement, raisng the plate above the surface, advancing the plate longitudinally of the pavement, and repeatng the cycle.

2. Concrete pavement groovng means comprising a v molding member carrying a plurality of depending spaced parallel ribs of shallow depth on the lower surface thereof, the areas of said member between said ribs being smooth and flush with one another, a machine movable longitudinally over the pavement, means mountng said molding member on said machine and operable for raising said member above the pavement and for pressing said member onto newly laid pavement while still plastic to imbed said ribs therein to their full depth and to press said smooth areas of said member against the pavement sur-face and for simultaneously moving said member over said surface, said member and said ribs having an appreciable dimension in the direction of movement thereof, said member extending longitudinally of the pavement, said ribs extending transversely of the pavement, and said machine including means for starting and stopping the machine and for reciprocating said member transversely of the pavement.

3. The groovng means of claim 2 wherein said ribs are downwardly tapered and are sharpened at their opposite ends to faciltate their entry into, removal from and reciprocation in the pavement.

References Cited UNITED STATES PATENTS 774,005 1 1/ 1904 Thies 94--45 775,110 11/1904 Jumper 94-45 2,125,254 7/ 1938 Creason 94-45 2,203,529 6/ 1940 Harvey 94-45 2,543,966 3/ 1951 Heltzel 94-45 2,643,595 6/1953 Jackson 94--48 3,208,361 9/ 1965 Bidwell 94-45 JACOB L. NACKENOFF, Primary Examiner 

